After I completed the tutorial: Start Developing iOS Apps Today
I got the same exception asked here: IOS Tutorial Exception (ToDo Sample)
and the app crashed but it would not crash if I started a debugging session and stepped through the code.
2015-05-04 16:09:51.569 ToDoList[9223:67681] -[AddToDoItemViewController textField:]: unrecognized selector sent to instance 0x7fe570d4eff0
2015-05-04 16:09:51.574 ToDoList[9223:67681] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[AddToDoItemViewController textField:]: unrecognized selector sent to instance 0x7fe570d4eff0'
Then I solved the mystery by reading out this post: IOS Tutorial Exception (ToDo Sample)
The reason was that I wrongly connected the text field to the #implemenation section instead of to the #interface section and it created some method that I deleted. Of course I forgot about that soon after that.
How could I have figured out myself without knowing anything of the above what was the reason to get that exception and where it came from?
Log message is telling you that something was trying to call -textField: method of your AddToDoItemViewController.
So the first step would be to check if that method is implemented - in your case it was not. You might have been confused by the presence of
#property(weak, nonatomic) IBOutlet UITextField* textField
but auto synthesis for property generates getter with the signature -textField, which is different from -textField: (latter takes one parameter, while former none).
The exception says that you're trying to access the textView property of AddToDoItemViewController, but it doesn't have one.
So your next step would've been to go and check that you have a property like that declared and being an outlet that it's properly connected in the Interface Builder.
Edit:
Sorry I wasn't paying enough attention.
The selector that it's trying to call is textField: so it must be a function starting like that. I assume you set the controller as a TextView delegate but didn't implement the required method.
Related
I made a game in Unity, and built it for iOS devices. The clients asked if we could implement WebTrends into the game, and so I followed this getting started guide for instructions on how to install it.
I was able to set it up, and got to Step 5, which suggests the following:
Lifecycle events can be logged automatically by setting the
wt_dc_automatics_enabled config setting to true
This is where I got stumped. I then added the above setting to my webtrends.plist, so it now looks like this:
When attempting to build and run that, I get an error in Xcode, and the game refuses to run:
Uncaught exception: NSInvalidArgumentException: -[__NSCFBoolean hasPrefix:]: unrecognized selector sent to instance 0x11294d238
This guide suggests setting wt_dc_enabled to true instead of wt_dc_automatics_enabled.
But even after replacing that in the plist, it returns the same error.
Notably, the project runs fine if I remove the wt_dc_automatics_enabled / wt_dc_enabled from the plist file, though it doesn't sent any logs, to my knowledge.
Is there anything else I can do?
Can you trying making wt_dc_automatics_enabled as String type and not boolean type and add its value as YES.
Because your error says somewhere in the code hasPrefix method is called on Boolean value. hasPrefix method is defined in String class and there is no such method in Boolean class.
I'm just learning Objective C and have come across this issue. I have created a simple manager class like so
#import <Foundation/Foundation.h>
#interface PassManager : NSObject
- (void)isValidCredentials:(NSString *) username
withPassword:(NSString *) password
wasValid:(void(^)(BOOL success))handler;
#end
the implementation is as follows
#import "PassManager.h"
#implementation PassManager
- (void)isValidCredentials:(NSString *) username
withPassword:(NSString *) password
wasValid:(void(^)(BOOL success))handler
{
handler(true);
}
#end
This builds but upon running I get the error:
"2016-01-27 16:40:41.555 MessyApp[19395:897750] -[PassManager initWithConfiguration:]: unrecognized selector sent to instance 0x7fd12a413d30 2016-01-27 16:40:41.560 MessyApp[19395:897750] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[PassManager initWithConfiguration:]: unrecognized selector sent to instance 0x7fd12a413d30'".
What am I doing wrong?
Well the error says it all, somewhere in your code you are calling the initWithConfiguration method on an PassManager but you don't have that method in your PassManager class, so it throws an exception.
Either add the method and implement it in your PassManager class, or if you want to catch exactly where this is happening (and don't want to search for all the occurrences of initWithConfiguration.
You could go to Breakpoint Navigator by pressing CMD+7 and then on the bottom press the + sign and add an Exception Breakpoint, run the app and wait for it to fire.
Good luck.
After speaking to originaluser2 he showed me it was something else causing the problem. I was using a library called Parse that required startup code in the appdelegate class and it was that what was blowing up. Once he showed me that I looked at what else I did and realised I had created a class called ParseManager that was causing some sort of name conflict. I changed this classes name and sure enough it all started working. Bad question on my part I'm afraid but Im a new to this platform
I am trying to add an observer to a NSNotificatonCenter notification that I posted in code earlier but Xcode gives that exception
Terminating app due to uncaught exception
'NSInvalidArgumentException', reason:
'+[TurkI_s_Manga.DisplayMangaViewController setStuff:]: unrecognized
selector sent to class 0x102ffd650'.
I am using the same structure three times in my code and only one of them causes that exception. So I tried to check the selector before try to use it like this:
println(self.respondsToSelector("setStuff:"))
if self.respondsToSelector("setStuff:"){
println("it responses to selector set stuff")
NSNotificationCenter.defaultCenter().addObserver(DisplayMangaViewController.self, selector: "setStuff:", name: "pagesNotification", object: UrlAndNameList.self)
}
This code block prints true and then it responses to the selector set stuff but when observer receives the notification it gives the exception mentioned above.
Any help would be appreciated, thanks.
From my above comment: You are adding the type (class) as an observer (which could work if setStuff is a type method). What you probably want is
NSNotificationCenter.defaultCenter().addObserver(self, ...)
to add the instance self as an observer.
You are checking whether one thing (self) responds to a selector, and then you add another thing (DisplayMangaViewController.self) as an observer, which doesn't respond to the selector. So please explain why you would think that's Xcode's fault and not your own mistake.
First rule of debugging: When things go wrong, it is your fault. You did something wrong. Find what you did wrong. There are millions of developers using Xcode. Do you really think if it got something trivial like this wrong, you wouldn't hear about it everywhere?
I have a Ruby on Rails application that has an API, it's an OAuth 2.0 provider and uses Doorkeeper. I am creating an iPhone client for that application and am using the gtm-oauth2 library for authentication. Here is the Github repository for the iPhone app.
I manage do the authentication request using the library and get the response from the OAuth server, but (I think that) when the iPhone app receives the response, the iPhone app crashes. I get the following error:
2013-03-25 07:30:51.563 Catapult for iOS[68917:c07] -[NSNull length]: unrecognized selector sent to instance 0x14f2678
2013-03-25 07:30:51.564 Catapult for iOS[68917:c07] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSNull length]: unrecognized selector sent to instance 0x14f2678'
*** First throw call stack:
(0x13c1012 0x11e6e7e 0x144c4bd 0x13b0bbc 0x13b094e 0xf074 0x185e3 0x13b51bd 0x13b50d6 0x1531a 0x1512b 0x14ae2 0x13b51bd 0x13b50d6 0x11d0a 0x1032a 0x13b51bd 0x13b50d6 0x79be 0x77ed 0x8cf2 0xcec589 0xcea652 0xceb89a 0xcea60d 0xcea785 0xc37a68 0x4a2a911 0x4a29bb3 0x4a67cda 0x13638fd 0x4a6835c 0x4a682d5 0x4952250 0x1344f3f 0x1344a39 0x1367734 0x1366f44 0x1366e1b 0x22be7e3 0x22be668 0x12affc 0x2c6d 0x2b95)
libc++abi.dylib: terminate called throwing an exception
I am a complete noob/beginner when it comes to iOS development and Objective-C programming, and I am learning how to create my first app using this little project. I asked the same question in the gtm-oaut2 Google Group and according to them, the problem comes from my code and not the library. The problem is that all of my code is taken from their wiki and I can't pinpoint where the app crashes. If I understand correctly, at some point I am calling length of NSNull, but I am not calling length anywhere, hence my confusion. Also, when the app crashes, the line hilighted is in the main.m file and the error (on the right label, not in the output) is the following:
Thread 1: signal SIGABRT
I have no clue what that means...
Does anyone know what the problem might be please?
You're right that the issue is that somewhere you've got the length message being sent to an instance of NSNull. To pinpoint where exactly this is happening set a breakpoint on objc_exception_throw. You can do this in the Xcode UI with little "+" button in the bottom left corner on the breakpoints tab. Select "Add Exception breakpoint." Then the debugger will stop your program at the point where the error occurs instead of waiting for the program to actually crash.
Well... you understood the error correctly.. You are somewhere calling length on a NSNull instance.
I must find out where this is happening.
I think this is happening in a JSON response. Maybe you (or "the code") is calling length on something it expects its a NSString but it is instead NSNull (that is the json has a NULL value).
Try if you manage to print the json response and see if you found a key mapped to a null value...
NSNull does not respond to length
You can check the documentation for NSNull to see that this is the case.
Without having an idea of what your code base is doing I am not sure where to look, you must be calling [NSNull null]; at some point to get the NSNull object or you are using a framework somewhere that returns this.
I'm trying to develop an app that can show a PDF file. I try to complete this with ZoomingPDFViewer
http://developer.apple.com/library/ios/#samplecode/ZoomingPDFViewer/Introduction/Intro.html#//apple_ref/doc/uid/DTS40010281-Intro-DontLinkElementID_2
code that is in the apple library. When I mix that code with my code some function doesn't work. And if I make it with the same code (don't mixed) the app throw this error:
* Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UIView setPDFPage:]: unrecognized selector sent to instance 0x6a833f0'
I'm in SDK 5.0 the requirements says that I should compile it in SDK 5.1 but the sample runs perfect, the problem is in my project but I don't know what is my error.
I'll appreciate if someone can help me with this strange error.
Check the Class setting in Storyboard.
View Controller -> Custom Class: ZoomingPDFViewerViewController and
Scroll VIew -> Custom Class: PDFScrollView
The second setting is the cause of your error.
You seem to be sending -setPDFPage: to an uncast self.view object. Try casting before calling like so:
[(PDFScrollView *)self.view setPDFPage:PDFPage];
Double check your connections in IB, if you are using it, or make sure you are initing a PDFScrollView* object in -loadView if not.